Axis-index for lenses.



J. E. LIMEBURNER.

AXIS INDEX FOR LENSES.

APPLICATION FILED 11113.21, 1912.

1,099,927, Patented June 16,1914.

I uvvsm on WITNESSES 4 6 x I 4, 44/

A TTORNE Y JOHN E. LIMEBURNER, OF SWARTHMORE, PENNSYLVANIA.

AXIS-INDEX FOR LENSES.

Specification of Letters Patent. Patented June 16, 1914;,

Application filed March 21, 1912. Serial No. 685,340.

To all whom it may concern Be it known that I, JOHN E. LIMEBURNER, acitizen of the United States, residing at 74-2 Harvard avenue,Swarthmore, in the county of Delaware and State of Pennsylvania, haveinvented a certain new and use ful Axis-Index for Lenses, of which thefollowing is a specification.

The purpose of my invention is to provide an axis index which is rigidlyconnected with the mount of the lens.

A, further purpose of my invention is to avoid one setting of the lenswithin a trial frame, reducing the time of operator and patient and alsoreducing the opportunity for errors.

A further purpose of my invention is to aline the index with the axismarking upon the lens within the laboratory or factory, rather than uponthe test frame.

A further purpose of my invention is to simplify the construction andincrease the accuracy of axis indication for lenses.

Further purposes of my invention will appear from the specification andthe claims appended thereto.

I have preferred to illustrate my inven tion by some forms thereof,which I have found to be practical, convenient and inexpensive, andwhich at the same time well illustrate the principles of my invention.

In the drawings Figure 1 is a front elevation of a structure embodyingtwo desirable forms of my invention. Figs. 2 and 8 are front elevationsof the lenses and mounts shown in Fig. 1. Fig. I is a broken frontelevation of another form of my invention.

It has been customary in the use of trial frames to set the lens in theframe with its axis mark as nearly as may be in alinement with an indexor indicator carried by the rotatable lens carrier, and to determine thelinal position of the lens by subsequently reading the position of thisindex upon the annular scale. This has involved two settings during theuse of the trial frame, with corresponding opportunity for error.Probability of error is much increased by the fact that the settings aremade while the frame is worn by the patient. 7

I have aimed to eliminate one of the settings under these unfavorableconditions, with corresponding gain in time, simplicity and accuracy, byfastening an index to the lens during manufacture, or under thefavorable conditions of laboratory work, preferably as a permanentfastening, and to use this index for the determination of the readingupon the annular trial frame scale.

In Fig. 1 I have illustrated the general structure of what is known asthe Rhoads trial frame, having adjustable bar 1, adjustable nose piece2, clamps 3 and 4, annular, non-rotatable scales 5 and (5, rotatablelens carriers 7, 8, posts 9, 10, lens clamps 11, front clamps l2,rotatable buttons 13 and gears 14, engaging with the teeth 15, upon thelens carriers. All of this structure is well known. I have supplied eachlens 16 with its own axis index, showing two forms thereof, 17 and 17. Ihave shown the index rigidly mounted upon the rim or frame 18 of thelens, which frame is retained about the lens in any suitable manner, asat 19, 19. I have preferred to place a handle upon the lens frame andshow this handle as an extension 20 of one side of the frame.

It will be evident that many forms of handle may be devised and locatedat any desired point about the circumference of the lens. Thedesirability of connecting it with the joint 19, lies in the fact thatthe form of joint preferred causes some extension from the circularcontinuity of the lens frame and provides convenient handle mount atthis point, leaving approximately the entire circumference of the lensframe of uninterrupted circular continuity for insertion within the lensholder. It will be likewise evident that the handle may be combined orconnected with the index, as in Fig. 2, where they are connected by anysuitable web or member 21. The handle and index may be entirelydisconnected as in Fig. 3. I prefer to locate them near together toleave as large a part as possible of the lens frame of circular form. Itwill be further evident that a wide variety of indexes may be used andthat the method of their attachment to the lens rim or frame is wholly amatter of selection with the manufacturer.

In Fig. 1, I have shown one form of lens axis index in one of thecarriers 7 and the other form illustrated in 8.

It will be evident that the extension Whose edge or point forms the axisindex may itself form the handle for the lens and lens frame, asindicated in the construction shown at 21 in Fig. 4.

lVhere the lens index is to extend from the lens rim or frame, themarking of the axis of the lens, as at 22, may be made very In operationthe lens needinot be prelimi-' narily adjusted in the revolving lensholder of the testing frame to bring it into line with. any markingsupon the rotatable lens holder, but can be placed in any position withinthe lens holder, and adjustment to meet the conditions of the eye beingtested can be begun at once. lVhen the lens has been turned to thecorrect position, the angle with respect to the axis, can be read directly from the index against the annular scale.

Having thus described my invention, What I claim as new and desire tosecure by Let ters Patent is 1. In a device of the character stated, aframe having angular scales thereon, a trial lens holder rotatable inthe frame, a trial lens removably supported in said holder, a

I rim surrounding the lens and rigidly secured With respect to it, andan axis index for the lens secured to the rim and projecting therefrom.

2. In a device of the character stated, a frame having angular scalesthereon, a trial lens holder rotatable in the frame, a trial lensremovably supported in said holder,

and an axillary index in fixed position therewith and exterior to thediameter of the lens.

3. In a device of the character stated, a frame having angular scalesthereon, a trial lens holder rotatable in the frame, a'trial lensremovably supported in said holder, a rim about the lens and rigidlysecured to it,

a handle upon the rim and an axis index (topics of this patent may beobtained for five cents each, by addressing the Commissioner of Estonia,Washington, .D. G.

